Key exporting countries have seen their share price fall
Asian share prices tumbled for a third day in a row as investors feared a global recession would badly hit company earnings.
Japan's Nikkei closed at a five-and-a-half year low, down 9.6% after the electronics giant Sony halved its full-year profit forecasts.
India's Sensex fell more than 10% to its lowest level in nearly three years.
South Korea's market plunged 10.6% as chip maker Samsung announced a 44% fall in its third-quarter profits.
Seoul's Kospi benchmark share index ended at 938.75 points, the first tim it has closed below 1,000 points since May 2005. It has lost more than half its value so far this year.
It is the Seoul market's worst weekly fall - 20.5% - since records began in 1987.
More records were set in Tokyo, where the Nikkei dropped below the 8,000-mark for the first time in more than five years.
Yutaka Miura, of Shinko Securities in Tokyo, said a profits warning from Sony was "yet another indicator that the global economy is really slowing".
"Investors remain worried over growing uncertainty about the state of the global economy," he said.
A strong yen is causing concerns about Japanese export earnings, as the US dollar fell below 96 yen, its lowest level for 13 years.
"The stronger yen is hurting Japanese exports, which is a big part of that country's economy," said Linus Yip, of First Shanghai Securities in Hong Kong.
Meanwhile Asian countries have re-committed themselves to establishing an US$80bn emergency fund, as leaders from across Asia and Europe gathered in Beijing to discuss the global financial meltdown.
The deal would enable countries to borrow from the fund when facing a liquidity crunch.
Elsewhere in Asia, India's central bank cut its economic growth forecasts for the year to 7.5% but warned that a deep and protracted global downturn was likely.
However, the bank left its key interest rate unchanged after its surprise cut earlier this week.
At one point India's Sensex fell below 9,000 for the first time in two years.
The Indian rupee fell to its lowest ever level against the US dollar before recovering some ground.
Hong Kong's Hang Seng and Singapore's Strait Times both fell 8.3% while in Sydney the ASX index fell 2.64%.
Thursday was another volatile trading day on Wall Street after a slew of weak corporate earnings stoked fears of a United States recession.
The main Dow Jones index fell as low as 8,251 points before closing the day up 172 points or 2% at 8,691.
The technology-heavy Nasdaq in contrast lost 0.73% to close at 1,603.9 points.
It was the Dow's first rise in three days and contrasts the sharp falls seen in Asia this week.